1. Field of the Invention
The present invention relates, in general, to rotary compressors for refrigeration cycles and, more particularly, to a rotary compressor, a capacity of which is variable as desired.
2. Description of the Related Art
As is well known to those skilled in the art, rotary compressors have been preferably and widely used as compressors for a variety of refrigeration systems, such as air conditioners or refrigerators operated with refrigerant sequentially and repeatedly flowing through a refrigeration cycle including compression-condensation-expansion-evaporation. In the refrigeration system, the compressor compresses the refrigerant to highly pressurize the refrigerant prior to discharging the highly pressurized refrigerant to a condenser.
As shown in FIG. 1, a conventional rotary compressor for refrigeration systems comprises a hermetic casing 1 with a drive device 2 and a compressing device 3 installed in the hermetic casing 1. The drive device 2 generates a rotating force, and the compressing device 3 compresses the refrigerant using the rotating force of the drive device 2. A rotating shaft 4 is axially arranged in the hermetic casing 1 such that the rotating shaft 4 is rotated by the rotating force of the drive device 2 and transmits the rotating force to the compressing device 3.
The compressing device 3 comprises variable compressing chambers 5 and a roller 6 rotatably set in a bore of the compressing device 3 to define the variable compressing chambers 5 in said bore. The roller 6 of the compressing device 3 is rotated in the bore by the rotating force of the rotating shaft 4, thus compressing the refrigerant in the chambers 5.
However, the conventional rotary compressors are fixed in capacities thereof, so to change a capacity of the conventional rotary compressor after the conventional rotary compressor is completely assembled is impossible. Therefore, the conventional rotary compressor cannot meet a change in a refrigerating load of refrigeration cycles during a use of the conventional rotary compressor, thus causing the refrigeration systems to sometimes excessively consume electric energy.